This wasn't me but I saw it happen. A friend of mine was working on his car back in the days when expandable metal bands were used on wristwatches. He inadvertently shorted the metal watchband between the positive post of the battery and the car body. It welded itself to both ends and for quite a number of seconds slowly burned its way into my friends arm. He has a permanent scar around his wrist in the pattern of that watchband.